Physical vapor deposition dual coating process

ABSTRACT

A machine for covering a substrate (FIG. 14, 540) by means of both cathodic arc plasma deposition (CAPD) (FIG. 2) and magnetron sputtering (FIG. 1) without breaking vacuum in a single chamber (FIG. 14, 421). A computer system monitors (FIG. 3, 403, 405) and controls all coating process parameters to coat in any sequence multiple thin film layers using either the CAPD or magnetron sputtering process. A rotating substrate table (FIG. 14, 470) used in conjunction with internal and external targets coats both sides of the substrate simultaneously.

FIELD OF THE INVENTION

The present invention relates to vacuum coating production systemutilizing both cathodic arc emission and magnetron sputtering processes.

BACKGROUND OF THE INVENTION Sputtering Processes

Over the past 30 years or so there have been numerous reviews ofsputtering and sputtering processes for film deposition.

Because there are so many interactions among parameters in sputteringsystems, it is impossible to separate them completely.

Typically, the target (a plate of the material to be deposited or thematerial from which a film is to be synthesized) is connected to anegative DC voltage supply (or an RF power supply). The substrate is thematerial to be coated and it faces the target. The substrate may begrounded, floating, biased, heated, cooled, or some combination ofthese. A gas is introduced to provide a medium in which a glow dischargecan be initiated and maintained. Gas pressures ranging from a fewmillitorr to several tens of millitorr are used. The most commonsputtering gas is argon.

When the glow discharge is started, positive ions strike the targetplate and remove mainly neutral target atoms by momentum transfer, andthese condense on the substrate to form thin films. There are, inaddition, other particles and radiation produced at the target, all ofwhich may affect film properties (secondary electrons and ions, desorbedgases, X-rays, and photons). The electrons and negative ions areaccelerated toward the substrate platform and bombard it and the growingfilm. In some instances, a bias potential (usually negative) is appliedto the substrate holder, so that the growing film is subject to positiveion bombardment. This is known variously as bias sputtering or ionplating.

In some cases, gases or gas mixtures other than Ar are used. Usuallythis involves some sort of reactive sputtering process in which acompound is synthesized by sputtering a metal target (e.g., Ti) in areactive gas (e.g., O₂ or Ar-O₂ mixtures) to form a compound of themetal and the reactive gas species (e.g., TiO₂).

Emission of Neutral Particles-The Sputtering Yield

The sputtering yield is defined as the number of atoms ejected from atarget surface per incident ion. It is the most fundamental parameter ofsputtering processes. Yet all of the surface interaction phenomenainvolved that contribute to the yield of a given surface are notcompletely understood. Despite this, an impressive body of literatureexists showing the yield to be related to momentum transfer fromenergetic particles to target surface atoms.

It is estimated that 1% of the energy incident on a target surface goesinto ejection of sputtered particles, 75% into heating of the target andthe remainder is dissipated by secondary electrons that bombard and heatthe substrates. An improved process called magnetron sputtering usesmagnetic fields to conduct electrons away from the substrate surfacethereby reducing the heat.

There are three basic effects that occur at a substrate during glowdischarge sputtering: (1) condensation of energetic vapor, (2) heating,and (3) bombardment by a variety of energetic species. The sum of all ofthese effects must be carefully controlled, and, since they are allinterdependent, this is sometimes difficult.

For a given target material both deposition rate and uniformity areinfluenced by system geometry, target voltage, sputtering gas, gaspressure, and power. All other things being equal, rates are linearlyproportional to power and decrease with increasing target-substrateseparation. The sputtering gas influences deposition rate in the sameway as it affects sputtering yields. As the gas pressure is increasedthe discharge current increases (increasing rate), but return ofmaterial to the target by backscattering also increases (decreasingrate). This is further complicated in some cases by increased Penningionization at higher pressures which increases the rate byself-sputtering. The sum of all of this leads to gas pressure or a smallrange of gas pressure at which the rate is a maximum, and this must bedetermined empirically for each application. The optimum pressure may beanywhere between a few mTorr and several tens of mTorr.

In general, for a given gas pressure there will be an optimumtarget-substrate separation to produce the best uniformity. For smalltargets (15-cm diameter) this separation is generally small (a fewcentimeters), while for larger targets, the optimum separation may beconsiderably larger (10-20 cm).

Unquestionably, the hallmark of the sputtering processes described isversatility, both in terms of materials that can be deposited andprocess parameters that can be adjusted to tailor the properties of thinfilms as desired. However, the sheer number of critical processparameters and their complex interrelationships can often make theseprocesses difficult to control. In general, these processes are found tobe most useful in applications requiring rather thin films (generally 1micron because of relatively low deposition rates) and/or in cases wherethe desired material simply cannot be deposited stoichiometrically anyother way.

The above portion of this patent application was reprinted withpermission from the publishers of Thin Film Processes, edited by John L.Vossen and Werner Kern (copyright Academic Press, Inc., New York, 1978,pp. 12-62).

Cathodic Arc Plasma Deposition

In the past ten years major advancements have been made in a relatedphysical deposition process called cathodic arc plasma deposition(CAPD).

In the CAPD process target material is evaporated by the action ofvacuum arcs. The target source material is the cathode in the arccircuit. The basic components of a CAPD system consist of a vacuumchamber, a cathode and an arc power supply, a means of igniting an arcon the cathode surface, an anode, a substrate and a substrate bias powersupply. Arcs are sustained by voltages typically in the range of 15-50V, depending on the target cathodic material employed. Typical arccurrents in the range of 30-400 A are employed. Arcing is initiated bythe application of a high voltage pulse to an electrode placed near thecathode (gas discharge ignition) and/or by mechanical ignition. Theevaporation occurs as a result of the cathodic arc spots which moverandomly on the surface of the cathode at speeds typically of the orderof 10² m/s. The arc spot motion can also be controlled with the help ofappropriate confinement boundaries and/or magnetic fields. The arc spotsare sustained owing to material plasma generated with the arc itself.The target cathodic material can be a metal, a semiconductor or aninsulator.

The CAPD process is a unique process and is markedly different fromother physical vapor deposition (PVD) processes. Some of thecharacteristic features of the CAPD process are as follows.

(i) The core of the CAPD process is the arc spot which generatesmaterial plasma.

(ii) A high percentage (30%-100%) of the material evaporated from thecathode surface is ionized.

(iii) The ions exist in multiple charge states in the plasma, e.g. Ti,Ti⁺, Ti⁺² and Ti⁺³ etc.

(iv) The kinetic energies of the ions are typically in the range 10-100eV.

These features result in deposits that are of superior quality comparedwith those from other physical vapor deposition processes. Some of theseadvantages are as follows.

(a) Good quality films over a wide range of deposition conditions, e.g.stoichiometric compound films with superior adhesion and high density,can be obtained over a wide range of reactive gas pressure andmetal/refractory evaporation rates.

(b) High deposition rates for metals, alloys and compounds withexcellent coating uniformity.

(c) Low substrate temperatures.

(d) Retention of alloy composition from source to deposits.

(e) Ease in deposition of compound films.

Cathodic Arc Emission Characteristics

The cathodic arc results in a plasma discharge within the material vaporreleased from the cathode surface. The arc spot is typically a fewmicrometers in size and carries current densities as high as 10 amps persquare micrometer. This high current density causes flash evaporation ofthe source material and the resulting evaporant consists of electrons,ions, neutral vapor atoms and microdroplets. The electrons areaccelerated toward the cloud of positive ions. The emissions from thecathode spots are relatively constant over a wide range of arc currentas the cathode spots split into a number of spots. The average currentcarried per spot depends on the nature of the cathode material.

It is likely that almost 100% of the material may be ionized within thecathode spot region. These ions are ejected in a direction almostperpendicular to the cathode surface. The microdroplets, however, havebeen postulated to leave the cathode surface at angles up to about 30°above the cathode plane. The microdroplet emission is a result ofextreme temperatures and forces that are present within emissioncraters.

The cathodic arc plasma deposition process was considered unsuitable fordecorative applications until recently, due to the presence ofmicrodroplets in the film.

Latest developments involving elimination of microdroplets in the CAPDprocess has provided a significant alternative to existing techniquesfor a wide range of decorative applications. The CAPD process offersadditional flexibility in the following areas:

(i) The control of deposition parameters is less stringent thanmagnetron sputtering or ion plating processes.

(ii) The deposition temperature for compound films can be adjusted tomuch lower temperatures thus allowing the ability to coat substratessuch as zinc castings, brass and even plastics without melting thesubstrate.

In summary, the CAPD process offers many advantages over the traditionalsputtering process noted above. However, certain decorative applicationsrequiring a thin film are best accomplished with a sputtering process.One such application is applying a thin coating of gold on jewelry.

This is due to the difficulty of eliminating microdroplets in gold,copper, and silver coatings in CAPD processes. Therefore, sputtering isthe preferred method today for depositing a thin gold coating fordecorative purposes.

Gold, however, is relatively soft. Under conditions of continuous use itdevelops a diffusely reflecting appearance and is simultaneously wornaway. See U.S. Pat. No. 4,591,418 (1986) to Snyder. A coating oftitanium nitride (TiN) using the improved CAPD process as disclosed inU.S. patent application Ser. No. 07/025,207 to Randhawa, incorporatedherein by reference, creates excellent color matching to gold. Thus, itis possible to deposit titanium nitride on an inexpensive jewelry piecewith Randhawa's improved CAPD process and then deposit real gold overthe titanium nitride. Jewelry with this unique two layer coating offersthe user a real gold plated piece plus a piece with the extremely wearresistant titanium nitride undercoat. Thus, if the real gold layerpartially wears away, then the color matched titanium nitride retainsthe look of real gold in the worn away portion of the piece.

A difficulty in sequential layers of gold and TiN is that gold and TiNadhere very poorly to one another. Until the present invention, it isbelieved that only two basic methods were known to create multiple goldand TiN coatings. The first method is taught by Snyder, supra, whichuses at least four interleaved layers of gold and TiN. The second methodis taught by U.S. Pat. No. 4,415,421 (1983) to Sasanuma. Sasanumateaches simultaneous sputtering by means of an electron beam threedifferent layers. Sasanuma attempts to overcome the poor adhesionbetween gold and TiN by including an intermediary layer of TiN and goldbetween the bottom layer of TiN and the top layer of gold.

The present invention overcomes these difficulties and provides aconvenient single system to enable the direct coating of gold over TiNwithout adhesion problems. The present invention includes an advancedCAPD process and a modern magnetron sputtering process in a singlemachine.

SUMMARY OF THE INVENTION

It is, therefore, the object of the present invention to provide amachine capable of sequentially producing a coating using the CAPDprocess and the magnetron sputtering process.

Another object of the present invention is to provide the machine with acomputer controlled sequencing system.

Another object of the present invention is to provide the machine with acommon substrate turntable for both processes.

Another object of the present invention is to provide the machine withthe capability to coat both sides of a workpiece simultaneously with oneprocess and then the other process.

Another object of the present invention is to provide the machine with acomputer controlled reactant gas subsystem which can mix various gaseswith either process.

Another object of the present invention is to provide the machine with avariable substrate bias voltage for enhanced process control.

Another object of the present invention is to provide the machine with acommon vacuum pumping system for both processes.

Another object of the present invention is to provide the machine with acommon cooling system for both processes.

Another object of the present invention is to provide a system whichallows pure gold to firmly adhere to a coating of a nitride or acarbonitride.

Another object of the present invention is to provide a system whichallows pure gold to firmly adhere to a nitride or a carbonitride or asuitably hardened substrate.

Another object of the present invention is to provide a system which cansimultaneously coat a substrate using a CAPD process and a magnetronsputtering process.

Other objects of this invention will appear from the followingdescription and appended claims, reference being made to theaccompanying drawings forming a part of this specification wherein likereference characters designate corresponding parts in the several views.

Certain terms used herein are defined below:

Crossover setpoint: A defined pressure in the vacuum chamber where roughpumping ceases and diffusion pump and cold trap pumping take over toreduce pressure to high vacuum.

Hi-vac: A short-hand expression for high vacuum.

MilliTorr: One thousandth of a Torr. See below.

Substrate: Refers to the objects being coated.

Torr: A unit of pressure; that pressure necessary to support a column ofmercury one millimeter high at zero degrees Celsius and standardgravity.

Plasma: A collection of charged particles containing equal numbers ofpositive ions and electrons and which is a good conductor of electricityand is affected by a magnetic field.

The basic magnetron sputtering process is disclosed in Thin FilmProcesses, supra. Improvements are disclosed in U.S. Pat. Nos. 4,162,954(1979) and 4,180,450 (1979) to Morrison, Jr. and assigned to theassignee of the present invention, Vac-Tec Systems, Inc. All thesereferences are hereby incorporated herein by reference.

The basic CAPD process has evolved over the past twenty years. U.S. Pat.Nos. 3,625,848 (1971) and 3,836,451 (1974) to Snaper and assigned toVac-Tec Systems, Inc. provide the origins of the basic process. U.S.Pat. Nos. 4,430,184 (1984) to Mularie and 4,724,058 (1988) to Morrison,Jr., both assigned to Vac-Tec Systems, Inc., provide improvements to thebasic CAPD process. A summary of the CAPD art is provided in "TechnicalNote: A Review of Cathodic Arc Plasma Deposition Processes And TheirApplications" by H. Randhawa and P. C. Johnson (Surface and CoatingsTechnology, 31 (1987 pp. 303-318). Further improvements to CAPDprocessing are disclosed in U.S. patent application Ser. No. 07/025,207to Randhawa and assigned to Vac-Tec Systems, Inc. All the abovereferences are hereby incorporated by reference herein.

The present invention is a production CAPD and sputter coating systemdesigned to deposit high performance metallurgical coatings onto a widevariety of substrates. It employs CAPD targets and sputter targets todeposit thin films of material onto substrates in a vacuum environment.

The sputter deposition process, using cathodes, is a relatively highvoltage, low amperage process adaptable to depositing virtually anymaterial. The process bombards the target material with positive ions,dislodging mainly neutral target atoms by momentum transfer. Thedislodged atoms condense into thin films on the substrates.

The CAPD process uses a relatively high amperage and low voltage toevaporate an electrically conductive target source material and condenseit onto the substrates to form a coating.

The preferred embodiment of the present invention employs two 5×24 inch(12.7×60.96 cm) CAPD targets and two 3.5×25 inch (8.89×93.5 cm) sputtertargets to generate materials to be deposited.

A substrate fixture bearing the substrates rotates in the chamber.Alternatively, the substrate may be variably passed in front of thetargets by means of planetary motion, oscillation, or reciprocation. Apotentiometer or variable controller varies the speed of rotationaccording to the requirements of the deposition process.

DC bias power can be applied to the substrate fixture and substrates,during the deposition process, to enhance the movement of the targetatoms toward the substrates and/or to effect the characteristics of thedepositing film.

A diffusion pump, polycold trap (Meissner Trap), a cryogenic pump, or aturbomolecular pump create and maintain high vacuum in the chamberduring the process. A mechanical pump evacuates the chamber to lowvacuum (rough vacuum) and pumps (draws the exhaust away from) thediffusion pump or turbomolecular pump during high vacuum pumping.

A programmable logic controller (PLC) manages the process sequences. Thesystem responds to the feedback of relevant processing parameters.Manual override is always available.

The major components of the present invention are:

1. the system main frame which supports and surrounds

the processing chamber,

the diffusion pump and polycold trap,

water and compressed air distribution panels,

mass flow controllers and valves for process gasses,

monitoring instruments, and

electrical terminal board.

2. the system control console containing the control instruments,

3. two CAPD target power supplies,

4. the mechanical pump,

5. the compressor for the polycold trap,

6. a power supply cabinet containing the power supplies for the targetsand bias,

7. the power distribution cabinet and transformer,

8. the programmable logic controller (PLC)

9. computer,

10. the software for the computer, and

11. the software for the PLC.

A Typical CAPD Process Cycle

The operator loads the fixture with substrates and closes the frontchamber door, sealing the chamber. The mechanical pump reduces pressurein the chamber to the crossover setpoint, typically set between 80 and150 milliTorr.

The chamber roughing valve closes when the chamber reaches the crossoversetpoint; the hi-vac valve opens a few seconds later. The closing of thechamber roughing valve isolates the mechanical pump from the chamber;the opening of the hi-vac exposes the chamber to the diffusion pump andpolycold trap.

The pump-down cycle ends when the diffusion pump reduces pressure in thechamber to a preset level, referred to as the base pressure andtypically 2×10⁻⁵ Torr. The drive motor then begins to rotate thesubstrate fixture.

The reduction of pressure to 2×10⁻⁵ Torr removes from the chamber mostof the gas and water molecules which would otherwise interfere with theprocess.

Typically, nitrogen flows into the chamber, raising the pressure to1×10⁻³ Torr or higher. The CAPD arc is then initiated. A high biascurrent initiates the cleaning cycle to clean the substrates with thesputtering action of ionized particles.

The high bias cycle ends and the deposition cycle begins. Nitrogen gasback fills the chamber to operating pressure--a pressure between 5 and20×10⁻³ Torr.

Typically, nitrogen molecules combine with molecules of the CAPD target(i.e. titanium) during the reactive deposition process to form a coatingof titanium nitride on the substrates; thus, the process consumes aportion of the nitrogen introduced into the chamber.

Nitrogen flows continuously into the chamber during the depositionprocess, requiring constant pumping by the high vacuum pump. The systembalances the flow rate of the nitrogen with the pumping rate to keeppressure in the chamber at its operating pressure setpoint.

The system adjusts the flow rate of nitrogen with a mass flowcontroller, which compensates for the effect of pressure on the densityof nitrogen and delivers standard volumes of gas regardless of pressure.

A negative voltage at the substrate accelerates the positively-chargedions of titanium en route from the targets. The negative voltage iscalled the bias voltage and is typically in the range of -50 to -500volts of direct current (VDC).

The titanium targets are consumed during the deposition process and mustbe replaced periodically.

CAPD targets are connected to the negative output of the arc powersupplies. Current flows from the arc targets through a plasma to ananode. Positively ionized particles of titanium, stripped from thetarget by the current, flow toward the negatively charged substrate,combining with nitrogen on the surface of the substrate to form thecoating.

The PLC shuts off the nitrogen and power to the CAPD target sources atthe conclusion of the deposition process and vents the chamber withnitrogen. When the chamber reaches atmospheric pressure, the PLCactivates an audible signal.

Sputtering

Sputtering is a relatively high voltage, low amperage, depositionprocess in contrast with a CAPD deposition process which employsrelatively high amperages and low voltages.

Positive ions, generated in the glow discharge of the plasma, strike thetarget on the cathode and dislodge mainly neutral target atoms bymomentum transfer.

The bombardment causes the target material to vaporize. Atoms dislodgedfrom the targets condense into thin films on the substrate.

The targets in the preferred embodiment measure 3.5 by 25 inches and arecooled by water.

Magnetron cathodes trap the plasma in a process chamber close to thetarget material by crossing electrical and magnetic fields. The erodingaction of the plasma on the targets yields a high sputtering rate perwatt of power.

The preferred embodiment of the present invention uses water cooledcathodes.

The operator may select from the following parameters from the PLC for asputtering deposition cycle:

Sputter process time,

Cathode #1 power setpoint,

Cathode #2 power setpoint, and

Sputter gas pressure

The operator selects the gas from the system control panel. Argon is thepreferred gas for the sputtering deposition process because of its mass.

The sputtering deposition cycle may also be automated If the chamber isat base pressure, then the operator initiates the automated process by:

1. Switching to SPUTTER from CAPD at the deposition select panel.

2. Entering the sputter parameters at the PLC.

3. Pressing process START on the system control panel.

4. Adding bias power if desired.

The completion of the above noted CAPD and sputter process in thepresent invention will produce brilliant gold plated jewelry or avariety of other coatings on any substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 Shows a schematic of a basic Planar Magnetron Sputtering System.

FIG. 2 Shows a schematic of a basic Cathodic Arc Plasma Deposition(CAPD) System.

FIG. 3 Shows a schematic of the major components of the Dual CoatingSystem of the invention.

FIG. 4 Shows a right side elevational view of the Dual Coating Systemmainframe having partial cutaways.

FIG. 5 Shows a left side elevational view of the Dual Coating Systemmainframe having partial cutaways.

FIG. 6 Shows the interior view of the right chamber door of the DualCoating System mainframe.

FIG. 7 Shows the interior view of the left chamber door of the DualCoating System mainframe.

FIG. 8 Shows a front elevational view of the Dual Coating Systemmainframe with the front chamber door and front enclosure panelscutaway.

FIG. 9 Shows a top perspective view of the back of the Dual CoatingSystem mainframe having cutaways of all enclosure panels and the uppersupport frame.

FIG. 10 Shows a top view of the mainframe of the Dual Coating Systemhaving all pumps removed.

FIG. 11 Shows a front elevational view of the left vacuum chamber doorof the Dual Coating System mainframe having the enclosure panelsremoved.

FIG. 12 Shows a front elevational view of the master control panel.

FIG. 13 Shows a front perspective view of the vacuum chamber portion ofthe Dual Coating System mainframe. The front and right side doors areremoved.

FIG. 14 Shows a front perspective view of the vacuum chamber andsubstrate fixturing.

FIG. 15 Shows a top view cross section of the vacuum chamber showing allmajor process cathodes.

FIG. 16 Shows a longitudinal sectional view of the internally mountedsputtering cathode taken along line A--A of FIG. 15 which is coincidentWith the line B--B of FIG. 13.

FIG. 17 Shows a longitudinal sectional view of the internally mountedCAPD cathode taken along line C--C of FIG. 15 which is coincident withline D--D of FIG. 13.

FIG. 18 Shows a front perspective view of a substrate clamp assembly forrings.

FIG. 19 Shows a software flow chart of the Program Logic Controller(PLC) logic.

FIG. 20 Shows a continuation of FIG. 19.

FIG. 21 Shows a software flow chart of the Personal computer (PC) logic.

FIG. 22 Shows a table of relative lusters and colors for various filmsproduced by the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to FIG. 1, a basic magnetron sputtering system comprisesa vacuum chamber 1, a pump system 2, and a sputtering gas source 3. Thevacuum chamber 1 houses a target/cathode 4 and an anode 5. Sputteringpower supply 6 biases the target/cathode 4 negative and the anode 5positive. The sputtering process uses a high voltage and low currentpower supply. A substrate 8 is a workpiece to be coated with a thin film9. Substrate 8 is biased negative by substrate power supply 7.

During the sputtering process the sputtering gas source 3 suppliesnon-reactant gas, argon. The pump system 2 maintains a vacuum in therange of a few milliTorr to a few tens of milliTorr. The sputteringpower supply 6 powers up, causing a glow discharge 10 between the anode5 and the target/cathode 4.

The glow discharge 10 causes positive ions of nonreactive gas, +, tobombard the target/cathode 4. See arrow 16. Momentum transfer causesneutral target atoms N, electrons e, and positive ions +, to dislodgefrom the target/cathode 4. Neutral target atoms N condense into thinfilm 9 on substrate 8. See arrow 14. Additionally a small percentage ofpositive ions + also condenses on the substrate. Positive ions + andelectrons e also bombard the substrate 8 while thin film 9 is growing.See the arrows 12 and 13.

A magnet 20 is located behind the target/cathode 4. The magnet 20creates a magnetic field around the target/cathode 4 as shown by lines22. The magnetic field 22 is typically in the order of a few hundredgauss. Magnetic field 22 traps a substantial number of electrons eagainst the target/cathode surface 23. This effect of trapping theelectrons e serves two basic purposes. First fewer electrons reach thesubstrate 8, thereby maintaining the substrate 8 at a coolertemperature. Second the constant motion of the electrons e attarget/cathode surface 23 enhances the sputtering yield, the emissionrate of neutral particles N, from the target/cathode surface 23. Thisenhanced sputtering yield allows a faster growing of thin film 9 on thesubstrate 8. Thus a manufacturing efficiency is realized by reducing thetime necessary to coat thin film 9 on substrate 8.

Referring next to FIG. 2 a basic cathodic arc plasma deposition (CAPD)system comprises a vacuum chamber 1, a pump 2, and an optional gassource 30. The vacuum chamber 1 houses a target/cathode 40 and an anode50. CAPD power supply 60 biases the target/cathode 40 negative and theanode 50 positive. The CAPD process uses a low voltage and high currentpower supply. A substrate 8 is a workpiece to be coated with a thin film90. Substrate 8 is biased negative with respect to ground by substratepower supply 70.

During the CAPD process at least one gas 33 is introduced into thevacuum chamber 1 by gas source 30. The pump system 2 maintains a vacuumin the range of 1×10⁻⁴ Torr to 1×10⁻³ Torr. The substrate power supply70 biases the substrate 8 to a high voltage in the range of 200 to 1000volts DC. RF voltages may be used for non-conducting materials.

Next the CAPD power supply 60 applies voltage to the target/cathode 40and the anode 50. Next the arc starter 44 ignites an arc 100 between thetarget/cathode 40 and the anode 50. An arc spot 29 forms on thetarget/cathode surface 230. The arc spot 29 moves at a speed of theorder of a hundred meters per second on the target/cathode surface 230.Multiple arc spots 29 are created by using higher arc currents. The arcspot 29 moves under the control of the magnet 200 in a predeterminedpattern. The magnet 200 produces a magnetic field 220 in the range of10-50 gauss. The arc spot(s) 29 is confined to the target/cathodesurface 230 by means of an insulating border 333.

The arc spot(s) vaporizes the target/cathode 40 thus forming a stream ofpositive ions +, electrons e, droplets D, and neutral atoms n. Thedroplets D are removed from the stream by means of deposition shields555. Droplet removal shields 555 are suitably placed in front and to thesides of target/cathode 40.

The electrons e flow to the anode 50 of the arc circuit. The positiveions +bombard the substrate 8 thereby cleaning and heating the substrate8.

After adequate cleaning, additional gas or gasses 33 are added into thevacuum chamber 1 to establish pressures in the range of 1×10⁻³ Torr to5×10⁻² Torr.

Next the substrate 8 is biased by substrate power supply 70 to a lowervoltage in the range of 50-200 volts DC or RF.

Maintaining the arc 100 causes the thin film 90 to grow on the substrate8 by the deposition of positive ions + and a small percentage of neutralatoms n. The thin film 90 thickness and the rate of deposition arecontrolled by varying the arc current, vacuum chamber 1 pressure, thesubstrate 8 bias voltage, the substrate temperature and the processtime.

Referring next to FIG. 3, the Dual Coating System 400 comprises amainframe 401, a master control panel 402, a programmable logiccontroller (PLC) 403, PLC software 404, a personal computer (PC) 405, PCsoftware 406, a power distribution panel 407, arc source power supplies408, 852, a substrate bias power supply 409, sputtering power supplies410, 575, a control unit for the cryogenic trap 411, and a mechanicalpump 452.

Referring next to FIG. 4 the right side of the Dual Coating mainframe401 has a support skeleton 412, leveling feed 413, enclosure panels 414,415, 416, 417, 418, 419, and 420, vacuum chamber 421, front chamber door422, right side chamber door 423, CAPD cathode 424, CAPD anode 425, arcstarter 426, process gas mass flow control valves 427, a flow sensor850, process gas supply pipe 428, a compressed air supply pipe 429, acompressed air pressure regulator 430, a compressed air filter 431, acooling water supply manifold 432, a cooling water flow control valve434, a cooling water safety switch 435, and an electrical terminal board436.

Multiple chamber doors 422, 423 serve to offer ease of access tointernal components for maintenance as well as flexibility in loadingand unloading workpieces. Compressed air components 429, 430, and 431operate the pneumatic valves in the Dual Coating System 400. Coolingwater components 432 and 434 distribute and control cooling water to theinternal chamber pipes 437. Inlet port 438 and outlet port 439 incombination with internal chamber pipes 437 and cooling water supplymanifold 432 form an internal water cooled surface 400 around vacuumchamber 421. Cooling water safety switch 435 working in conjunction withmaster control panel 402 shuts off all power if cooling water flow dropsbelow a predetermined setpoint. The electrical terminal board 436 servesas the common termination point for all wiring to the mainframe 401.

Referring next to FIG. 5, mainframe 401 has enclosure panels 441, 442,443, 444, 445, 419 and 420, left side chamber door 446, cooling waterfilter 447, cooling water regulator 448, sputtering cathode 449,sputtering anode 464, and high vacuum pumping port 450.

Mainframe 401 has three chamber doors 446, 422 and 423 for process andmaintenance flexibility. High vacuum pumping port 450 connects to thecryogenic trap 489 and the diffusion pump 451 (FIG. 9).

Referring next to FIG. 6, the right chamber door 423 contains the sameinternal chamber pipes 437 as the rest of the chamber. Flexible hoses453 and 454 carry cooling water into the right chamber door 423.

A deposition shield 455 overlays the water cooled surface 440.Deposition shield 455 is generally made of stainless steel and serves toprotect the underlying surfaces from the deposition processes.

A viewport 456 allows users to peer into the vacuum chamber 421. Aviewport shutter 457 is manually placed in front of the viewport 456 toprotect the viewport 457 from the deposition process.

Referring next to FIG. 7, the left chamber door 446 has internal chamberpipes 437 and flexible hoses 458 and 459, and deposition shield 455. Adoor mounted sputtering cathode 460 is powered during the sputteringprocess. A door mounted CAPD cathode 461 is powered during the CAPDprocess. Sputtering anode 463 and CAPD anode 462 are shown. Arc starter465 starts the vacuum arc during the CAPD process.

The substrate temperature monitor 466 is an infrared sensor.

Referring next to FIG. 8, vacuum chamber 421 houses internally mountedCAPD cathode 424 and the corresponding CAPD anode 425, the CAPD cathodemounting bracket 468, internally mounted sputtering cathode 449, and thecorresponding sputtering anode 464, the sputtering cathode mountingbracket 467, door mounted sputtering cathode 460 and the correspondingsputtering anode 463, a second substrate temperature infrared sensor469, the substrate turntable 470, and the substrate mounting fixture471.

The substrate turntable 470 rotates under the control of the mastercontrol panel 402 during either the sputtering or CAPD process. Thesubstrate mounting fixture 471 is custom designed for varioussubstrates.

A substrate turntable drive assembly 472 comprises a drive motor 473, adrive belt 474, a turntable drive shaft 475, a rotary vacuum seal 476,substrate bias voltage connection 477, and the substrate bias voltagecable 478.

Drive motor 473 is a variable speed unit enabling precise control of thesubstrate turntable 470 speed. The rotary vacuum seal 476 maintains theintegrity of the vacuum chamber 421 during processes. The bias voltagecable 478 connects to the substrate bias power supply 409 (FIG. 3).

Referring next to FIG. 9, the Dual Coating System pumping assembly 479is shown. The pumping assembly 479 starts with the mechanical pump 452.Mechanical pump 452 pumps the vacuum chamber to a crossover pressureranging from 60 to 90 mTorr. Mechanical pump 452 connects to the vacuumchamber 421 through the inlet pipe 480, the inlet filter 481, theconnector pipe 482, the roughing valve 483 and the chamber roughing port484.

Thermocouple gauge 485 measures vacuum chamber 421 pressure andtransmits this pressure to the master control panel 402 (FIG. 3). Whenthe vacuum chamber 421 pressure reaches a predetermined crossoverpressure ranging from 60 to 90 mTorr, the master control panel 402closes the roughing valve 483 and opens the foreline valve 485 and opensthe high vacuum valve 487. These valve actions connect the mechanicalpump 452 in series with the diffusion pump 451. These serial pumps 451and 452 are connected to the vacuum chamber 421 through the high vacuumpiping 488 and the cryogenic trap 489 and the throttle valve 490 and thehigh vacuum valve 487 and the chamber high vacuum port 450 (FIG. 5).

After the above noted crossover procedures are accomplished, themechanical pump 452 maintains the diffusion pump foreline 491 at lowpressure while the diffusion pump 451 further reduces the vacuum chamber421 pressure to a system base pressure ranging from 2×10⁻⁵ to 5×10⁻⁷Torr. Simultaneously the cryogenic trap 489 condenses water vapor andother condensable gasses thereby increasing the efficiency of thediffusion pump 451.

Process pressures are controlled by the master control panel 402operating the throttle valve 490 in response to signals from thecapacitance manometer sensor 492. The foregoing control loop is known asa downstream pressure control system. The infrared temperature sensor493 views the substrates 540 through viewport 469, (see FIG. 8) therebyproviding the temperature control signal to the master control panel402.

When processing is complete the vacuum chamber 421 is raised back toatmospheric pressure by means of vent valve 494.

Referring next to FIG. 10, the top of the vacuum chamber 495 is seensupported by the support skeleton 412. Water inlet 497 provides coolingwater to the internal chamber pipes 437 as supplied by the cooling watersupply manifold 432, see FIG. 4. Water outlet 499 is then returned tothe cooling water supply manifold 432.

CAPD cathode utility plate 500 contains the electrical power leads 501to the anode and 502 to the cathode of the CAPD cathode 424 and CAPDanode 425 as seen in FIG. 4. Anode cooling water inlet 503 feeds CAPDanode 425, and the anode cooling water outlet 504 returns to the coolingwater supply manifold 432. Insulating enclosure 505 protects the CAPDcathode utility plate 500 from anode electricity. Cooling water inlet591 supplies cooling water from the cooling water supply manifold 432(FIG. 4) to the CAPD cathode 424. An outlet 592 returns the coolingwater to the cooling water supply manifold 432.

Sputtering cathode utility plate 506 contains the electrical power leads507 to the anode and 508 to the cathode of the sputtering anode 464 andsputtering cathode 449 as shown in FIG. 5. Insulating enclosure 590insulates the sputtering cathode utility plate 506 from electricity.Cooling water inlet 496 provides cooling water to the sputtering cathode449 from the cooling water supply manifold 432. Cooling water returnprovides the return to cooling water supply manifold 432.

Electric power for the arc starter 426 is supplied by leads 509 and 510.Electric power for the CAPD cathode electromagnet 530 is supplied bycable 531.

Shield armature 512 (see FIG. 15) is activated by activating assembly511. Activating assembly 511 consists of a pneumatic cylinder 515 andcrank arm 516.

Vacuum chamber 421 pressure is sensed and transmitted by pirani gauge517, thermocouple gauge 518 and ion gauge 519. Pirani type gauge 517measures pressures ranging from atmospheric to 1 mTorr. Thermocouplegauge 485 measures pressures ranging from atmospheric to 1 mTorr. Iongauge 519 measures pressures ranging from 1 mTorr-0.0001 mTorr.Thermocouple gauge 518 triggers the master control panel 401 forswitching the ion gauge 519 on.

Referring next to FIG. 11, the vacuum chamber 421 is seen supported bythe support skeleton 412. The left vacuum chamber door 520 opens forloading and maintenance. An enclosure panel 521 is cut away. Water inlet522 and water outlet 523 feed the internal chamber pipes 437 from thecooling water supply manifold 432. Water inlet 593 supplies coolingwater from the cooling water supply manifold 432 to the door mountedCAPD cathode 461. Outlet 594 returns the cooling water through thecooling water supply manifold 432.

The door mounted CAPD cathode 461 is mounted inside CAPD door enclosure524. Power to the door mounted CAPD cathode is supplied by lead 525.Power to the CAPD anode 462 is supplied by lead 526. Cooling water inlet527 supplies cooling water from the cooling water supply manifold 432 tothe door mounted CAPD anode 462 as shown in FIG. 7. Cooling water return528 supplies the return to cooling water supply manifold 432.

Electrical insulating enclosure 529 electrically isolates the doormounted CAPD anode 462. Electrical insulating enclosure 532 electricallyisolates the door mounted CAPD cathode 461. CAPD electromagnet 530 (FIG.17) is powered by cable 533. Water inlet 534 supplies cooling water fromthe cooling water supply manifold 432 to the door mounted sputteringcathode 460 (see FIG. 7). The water returns via water outlet 535. Lead536 powers the door mounted sputtering cathode 461. Leads 537 and 538power the arc starter 465 (FIG. 7).

An infrared sensor 539 measures the substrate 540 temperature as shownin FIG. 8. The infrared sensor 539 consists of a lens assembly 541, afiber optic cable 542, and the infrared sensing unit 543. Infraredsensing unit 543 measures and transmits the substrate 540 temperature tothe master control panel 402. High intensity light source 544 calibrateslens assembly 541. Enclosure safety switches 560 prevent operation if anenclosure panel is ajar.

Referring next to FIG. 12, the master control panel 402 consists of asubstrate temperature transmitter 545 which indicates temperatures fromthe infrared sensors 493 and 543 by means of gauge 546.

Substrate temperature transmitter 545 switches between infrared sensingunits 493 and 543 and subsequently transmits the substrate temperaturesto the programmable logic controller (PLC) 403.

The vacuum chamber pressure monitoring panel 547 consists of athermocouple gauge indicator 548 which senses inputs from thethermocouple sensor 518 (FIG. 10). The ion gauge indicator 549 sensesinputs from the ion tube 519 (FIG. 10). The pirani gauge indicator 550senses inputs from the pirani gauge sensor 517. Additionally the piranigauge indicator 550 transmits signals to the valve control panel 551which in turn controls the roughing valve 483, the high vacuum valve487, and the vent valve 494. The valve control panel 551 also controlsthe diffusion pump foreline valve 486 and the throttle valve 490 (FIG.9).

The system control panel 552 consists of a drive motor 473 speedindicator/controller 553. Additionally the system control panel 552provides a manual/automatic mode of operation by means of selectorswitch 554. Manual control switch 558 offers manual control of theprocess gas mass flow control valve 427 (FIG. 4). To initiate either theCAPD or sputtering process master start switch 556 must be switched"on". Process termination may be manually accomplished by switching theprocess stop switch 557 "off". A process status board 559 indicates thestatuses of vacuum chamber 421 pressure range, cooling water safetyswitch 435 (FIG. 4), enclosure safety switch 560 (FIG. 11) status, drivemotor 473 overtorque indicator (FIG. 8), and the overall process enablestatus indicator.

The process selection panel 561 provides selection of either the CAPD orsputtering process by means of selector switch 562.

The arc control panel 563 displays the respective CAPD voltages andamperages by means of indicators 564, 565, 566, and 567. The operatormay manually select whether to use one or both of the CAPD cathodes424/461 by means of selector switches 568 and 569. The CAPD arc powermay be manually controlled by potentiometers 570 and 571.

Varying substrate 540 surface areas require varying bias powerrequirements. Substrate bias power control module 572 controls the biaspower supply 409 and indicates bias voltage by means of indicator 851.The internal sputtering cathode controls the internal sputtering powersupply 410. The door mounted sputtering cathode power control module 574controls the door mounted sputtering power supply 575 (FIG. 3). Powerindicators 853 and 854 integral to the sputtering cathode controlmodules 573 and 574 indicate the electrical power levels of therespective sputtering cathodes.

The capacitance manometer sensor 492 (FIG. 9) transmits a signal to thecapacitance manometer controller 576. The vacuum chamber 421 pressure isindicated by the indicator 577 integral to the capacitance manometercontroller 576. Additionally, the capacitance manometer controller 576provides an input signal to the process gas controller 578.

The process gas controller 578 displays the process gas flow by means ofindicator 579. Flow sensor 850 (FIG. 4) supplies input to the indicator579. The process gas controller 578 modulates process gas mass flowcontrol valve 427 in response to signals from the capacitance manometercontroller 576, thereby controlling vacuum chamber 421 pressure. Theforegoing control loop constitutes an upstream pressure control system.

Support panel 581 houses the PLC input module 582. PLC input module 582is used to key enter variable data into the PLC 403. The PLC 403contains PLC software 404 which automatically can control all the CAPDand sputtering process functions for the Dual Coating System 400.

FIGS. 13, 14 and 15 show the spatial relationships of the main operatingcomponents of the Dual Coating System 400. FIG. 13 shows the substrateturntable 470. The internally mounted CAPD cathode 424 is supportedabove and in close proximity to the substrate turntable 470 by means ofthe CAPD cathode mounting bracket 468. The corresponding CAPD anode 425and arc starter 426 are commonly mounted to the same CAPD cathodemounting bracket 468. Utility cable 596 and 597 house cooling waterpipes and electrical conductors serving the internally mounted CAPDcathode 424.

The internally mounted sputtering cathode 449 and corresponding anode464 are mounted on the sputtering cathode mounting bracket 467.Corresponding utility cables 598 and 599 house cooling water pipes andelectrical conductors serving the internally mounted sputtering cathode449.

The door mounted sputtering cathode 460 and its corresponding anode 463faces the internally mounted sputtering cathode 449 such thatsimultaneous sputtering coating on both sides of the substrate 540 canbe accomplished.

The door mounted CAPD cathode 461 coats the outside of the substrate 540while the internally mounted CAPD cathode coats the inside of thesubstrate 540. The corresponding CAPD arc starter 465 and anode 462 aremounted on the same left chamber door 446. The substrate temperaturemonitor 466 protrudes beyond the deposition shield 455.

FIG. 14 shows a typical mounting arrangement for small substrates suchas rings. The substrate turntable 470 is in electrical contact with thesubstrate mounting fixture 471 which in turn is in electrical contactwith the substrate 540.

FIG. 15 shows in dotted lines how the shield armature 512 moves thesputtering cathode shields 513 and 514 away from the sputtering cathodes449 and 460 during the sputter coating. The shield armature 512 shown insolid lines moves the sputtering cathode shields 513 and 514 in front ofthe sputtering cathodes 449 and 460 to protect them from being coatedduring the CAPD process.

An alternate embodiment (not shown) uses RF sputtering cathodes eitherin addition to or in lieu of the magnetron sputtering cathodes 449 and460. Additionally RF substrate biasing (not shown) may be used.

A second alternate embodiment (not shown) uses diode sputtering eitherin addition to or in lieu of the magnetron sputtering cathodes 449 and460.

The droplet removal shields 555 (see FIG. 2) serve to remove alldroplets D from the stream of positive ions, electrons, and neutralatoms vaporizing from the door mounted CAPD cathode 461 and theinternally mounted CAPD cathode 424.

Referring to FIG. 2, the droplets D comprise molten metal particleswhich if allowed to land on the substrate 8 result in rough and lowluster films. This is unacceptable for decorative applications. It hasbeen experimentally determined that droplets D are emitted at angles θor less. θ has been found to be 30 degrees or less when the CAPD target615 (FIG. 17) has a minimal area of ten square inches. The distance 557of the droplet removal shields 555 and the opening 556 are selected toprohibit the droplets D from reaching the substrate 8 (FIG. 2).

The main purpose of the present invention is to provide a film having ahigh luster and a consistent color controllable to match various goldcolors. FIG. 22 shows a sampling of films produced by the presentinvention. Sequence Numbers 8 and 9 list the 10 carat and 24 carat goldcharacteristics used herein as a standard. L* denotes the luster orbrilliance of the film as measured per the CIE Lab color coordinates. a*denotes a range of red to green contents in the film. Positive a* valuesdenote red contents and negative a* values denotes green contents in thefilm. b* denotes a range of yellow to blue contents in the film. Thepositive b* values indicate a high yellow content in the film. Negativevalues would indicate a blue content in the film.

Sequence numbers 1 through 7 show specific film characteristics producedby the CAPD process used in the Dual Coating System 400. Referring toFIG. 19, Block 1006 varies the ratios of two process gasses (FIG. 2, 33)which comprise acetylene as a source of carbon, and nitrogen. Suitablyadjusting the ratios of carbon and nitrogen in the titanium andzirconium based films results in the excellent matching of luster andcolor film characteristics relative to gold as shown in FIG. 22. Thus inthe typical Dual Coating System 400 operation a CAPD film is producedfrom the above noted FIG. 22 Sequence Numbers 1 through 7. Next a goldfilm may be applied using the sputtering process as shown in FIG. 1.

The preferred embodiment produces in sequence the above noted two filmsduring a single vacuum cycle (FIG. 19 Block 1004). The adhesion of asecond film consisting of gold on top of a CAPD deposited film takenfrom the selection in FIG. 22 Sequence Numbers 1 through 7 iscommercially acceptable. A commercially acceptable adhesion isdetermined by using a Scotch Tape Pull test. This test results in nogold removal.

The ultimate purpose of the Dual Coating System 400 is to provide asingle system which enables the direct coating of gold over TiN or ZrNwithout adhesion problems. In practice the gold wears off the substrate8 (FIG. 1) thus exposing the TiN or ZrN film underneath. It is criticalin the practice of the present invention that the substrate 8 maintainthe same appearance as the gold film wears off. Thus the relative valuesin FIG. 22 Sequence Numbers 1 through 7 in relation to Sequence Numbers8 and 9 are critical to the successful practice of the presentinvention.

FIG. 16 shows the internally mounted sputtering cathode 449 andcorresponding anode 464 as seen in FIGS. 5, 8, 13 and 15. Internallymounted sputtering cathode 449 is comprised of cathode body 600,sputtering target 601, and magnet 602. Clamp 603 fastens the target 601to the cathode body 600 and completes their electrical continuity. Lead508 powers the internally mounted sputtering cathode 449. Cooling waterinlet 496 supplies water to the cooling water passage 604 therebycooling the target 601. Outlet 498 returns the cooling water to thecooling water supply manifold 432 (FIG. 4). O-ring 643 provides awaterproof seal between the target 601 and cathode body 600.

Corresponding sputtering anode 464 comprises an anode body 605, a darkspace shield 606 and a utility hub 607. The dark space shield 606restricts the plasma discharge to the target 601. The dark space shieldis affixed to the anode body 605 by means of screws 608. The sputteringanode 464 is insulated from the internally mounted sputtering cathode449 by means of insulators 610, Teflon bolts 609, and insulating ring611. O-rings 612 and 613 maintain a vacuum seal between utility conduits598 and 599 and the vacuum chamber 421.

FIG. 17 shows the internally mounted CAPD cathode 424 as seen in FIGS.4, 8, 13, and 15. Internally mounted CAPD cathode 424 is comprised ofcathode body 614, CAPD target 615, target edge insulating strip 616,cathode body insulation 617, cathode shroud 618, and magnet 530. Cathodeshroud 618 is insulated from the cathode body 614 by means of insulators619, 620 and 621 and Teflon screws 622. Target edge insulating strip 616is fastened to the CAPD target 615 by means of insulating fasteners 623.O-ring 624 provides a vacuum and water seal between the cathode body 614and the CAPD target 615. Cooling water passage 625 is supplied withcooling water from inlet 591, thereby cooling the CAPD target 615.Outlet 592 returns the cooling water to the cooling water supplymanifold 432. O-rings 626, 627, 628, 629, 630 and 631 maintain a vacuumseal between the cathode body 614 and cathode shroud 618 and the utilitycables 596, 597 and 632. Utility cables 596, 597 and 632 connect to thecathode shroud 618 by means of connection hubs 633, 634 and 635.

Power to the electromagnet 530 is supplied by cable 531. Gasket 636maintains a water tight seal between the electromagnet 530 and thecathode body 614. Power to the CAPD cathode 424 is supplied by lead 637and 638 via connectors 639 and 640. Insulating sleeves 641 and 642insulate connectors 639 and 640 from the cathode shroud 618.

Referring next to FIG. 18, the substrate turntable 470 has a mountingsurface 702 which supports the substrate mounting fixture 471. Thesubstrate mounting fixture 471 further comprises a base column 701, anda variable length rod 704. A substrate clamp 703 is affixed to thevariable length rod 704. Substrate clamp 703 has a flexible springconsistency. A triangular shape supports the substrate 540 in threespots. A ring, bracelet, earring or similar shaped substrate can befirmly secured with minimal contact against the substrate clamp 703.

Referring next to FIG. 3, the PLC 403 has the following basic hardwarecapabilities:

Memory for storage of an operating system

Memory for storage of a process program

Logic Module process program execution

Logic module for input/output control

The PLC software 404 has the following basic functional capabilities:

An operating system for controlling the PLC hardware

A process program ladder logic module

Referring next to FIG. 19, block 1000 shows the PLC operating systemstarting up and checking hardware diagnostics to ensure a fullyfunctional PLC exists before proceeding further.

Block 1001 shows the PLC reading all of the Dual Coating System 400signal inputs including substrate temperature transmitter 545, coolingwater safety switch 435 status, enclosure panels 414, 415, 416, 417,418, 419 and 420 status, thermocouple sensor 518 measuring vacuumpressure, ion tube 519, pirani gauge sensor 517, valve control panel551, drive motor 473 speed indicator/controller 553, manual/automaticselector switch 554, CAPD or sputtering process master start switch 556,selector switch 562, process termination switch 557, cooling watersafety switch 435, enclosure safety switch 560, voltage and amperageindicators 564, 565, 566, and 567, CAPD cathode selector switches 568and 569, substrate bias control module 572, internal sputtering powersupply 410, door mounted sputtering cathode power control module 574,power indicators 853 and 854, capacitance manometer sensor 492, and theprocess gas controller 578.

Block 1002 shows the PLC 403 receiving variable recipe data from eitherthe PC 405 or PLC input module 582.

Additionally the PLC 403 can send data to the PC 405 or to the PLC inputmodule 582.

Block 1003 checks for a safe system including cooling water safetyswitch 435 status, enclosure panels 414, 415, 416, 417, 418, 419 and 420all closed, and the thermocouple gauge indicator 548 which must show avacuum exists before proceeding further. Therefore, the program logicfirst assures that the Dual Coating System 400 has adequate water flowand has all safety covers in place and has all doors and openings sealedthereby ensuring a secured vacuum chamber 421.

Block 1004 shows the logic for the sequencing of the mechanical pump452, diffusion pump 451 and the cryogenic trap 489.

Block 1005 shows the logic for selecting whether to proceed with CAPD orsputtering by reading selector switch 562.

Block 1006 shows the logic for controlling the CAPD process gas by meansof the process gas controller 578 which controls the mass flow controlvalves 427, and variable input process parameters from Block 1002. ThePLC logic generates an error signal for pressure deviating from setpoint, and adjusts the mass flow control valves 427 accordingly.

Block 1007 shows the first process specific step for the CAPD process.This first step requires enabling the CAPD power supplies 408 and/or852. Next the CAPD magnet 530 is enabled. Next the substrate bias powersupply 409 is enabled. Next the substrate turntable 470 is activated.Next the substrate bias power supply 409 is controlled to the commandvoltage as received from Block 1002. Next the arc starter(s) 426, 465ignite the arc(s).

The user has inputted a substrate temperature parameter into Block 1002.Now in Block 1008 the substrate temperature is brought up to setpoint bymeans of varying the CAPD power supplies 408 and 852, and the substratebias power supply 409.

Blocks 1009, 1010, 1011, 1012 execute time versus power consumption andsubstrate temperature setpoint recipes which have been input into Block1002.

Block 1012 terminates the CAPD process after a predetermined amp hoursetpoint as received from Block 1002.

Block 1013 dictates whether to proceed with a sputtering process aspredetermined from Block 1002.

Block 1014 proceeds to an orderly shutdown by allowing the internalchamber pipes 437 to cool the substrate 540 to a predeterminedtemperature as dictated by Block 1002.

Block 1015 executes either an atmospheric vent by opening vent valve494, or by introducing process gas by means of process gas controlvalves 427.

The sputtering process is started in Block 1016 by introducing processgases by means of the process gas controller 578.

Next, Blocks 1017, 1018 move the sputtering cathode shields 513, 514 infront of the sputtering cathodes 464 and 463. Block 1017 proceeds topower the sputtering power supplies 410, 575 in order to sputter cleanthe sputtering target/cathodes 449 and 460. Time duration for sputtercleaning is dictated by Block 1002.

Next, Block 1019 removes the sputtering cathode shields 513 and 514 awayfrom the sputtering target cathodes 449 and 460. The substrate turntable470 is activated.

Next, Block 1020 sputters for a predetermined time and sputtering powersupplies 410, 575 supply power output as determined by block 1002.

Sputtering terminates with Blocks 1014 and 1015.

Block 1100 shows the PC running executive software and receivingvariable process recipes. Variable process recipes include all time,temperature, power, flow and pressure variables the user desires for hisprocess. Block 1101 shows the CRT on the PC displaying the variableinput recipes. An optional print output Block 1102 is shown.Alternatively the variable process recipes may be entered by means ofthe PLC input module 582.

Block 1103, shows the PC translating the variable input recipes fromengineering units to PLC format data. Block 1104 shows the PC 405storing and retrieving the variable input recipes.

Block 1105 controls all PC/PLC communications. Block 1106 shows the PLC403 receiving the variable input recipes. Additionally, the PLC 403 canbe commanded by the PC 405 to transmit measured process parameters fordisplay and storage by the PC 405.

Variable process recipes can be inputted into Block 1100 concurrentlywith the execution of measured process parameter displays and storage inBlocks 1101, 1102 and 1104.

The best mode for practicing the above noted computer art utilizes aTexas Instruments Series 500 PLC Model 530 C-1102. The PC used herein isan IBM (or compatible) using a Microsoft operating system, MS-DOS, andEGA/VGA graphics. EGA/VGA graphics allow sixteen color displays,primitives and text. Asynchronous serial communications between the PLCand the PC utilize Texas Instruments Task Codes and assembly languageroutines.

The PLC ladder logic software is written using the Texas InstrumentsTisoft Ladder Editor. The PC executive software is written in the "C"language using the Microsoft C compiler.

The executive software for the PC is menu driven thereby allowing thescreen to prompt the user into entering variable recipes in engineeringunits. On line "help" prompts are available to the user as an exit fromall screens. The executive software accepts all data in engineeringunits and converts all data to PLC machine readable data using "C"language subroutines.

The CRT Block 1101, printer Block 1102 and disk Block 1104 can receiveand display or print or store all variable input process parameters inreal time.

We claim:
 1. A method for sequentially depositing discrete first andsecond thin film coatings on a substrate, comprising the steps of:a)placing the substrate in a chamber; b) evacuating the chamber; c)activating a CAPD target/cathode in the chamber; d) depositing one ofsaid thin film coatings by CAPD on the substrate; e) deactivating saidCAPD target/cathode; f) injecting a process gas into the chamber; g)activating a magnetron sputtering target/cathode in the chamber aftersaid CAPD target/cathode is deactivated; h) creating a plasma dischargein the chamber; and i) depositing one of said thin film coatings bymagnetron sputtering on the substrate.
 2. The method for depositingmultiple thin film coatings on a substrate in claim 1, furthercomprising the steps of:(i) cooling the chamber; (j) controlling all theforegoing process steps by means of a computer system.
 3. The method fordepositing multiple thin film coatings on a substrate in claim 1,further comprising the steps of:(k) shielding the CAPD droplets from thesubstrate.
 4. The method for depositing multiple thin film coatings on asubstrate in claim 1, further comprising the steps of:(l) controllingthe thin CAPD film to be substantially the same luster and color asgold.
 5. The method for depositing multiple thin film coatings on asubstrate in claim 1, further comprising the steps of:(m) controllingthe thin sputtering film to be firmly adhered to the thin CAPD film. 6.The method for depositing multiple thin film coatings on a substrate inclaim 1, wherein the chamber vacuum is not broken between the CAPDdeposition and the sputtering deposition except by injecting of theprocess gas.